SCIENCES DU VEGETAL

CRISPR and TALENs are efficient systems for gene editing in many organisms including plants. In many cases the CRISPR–Cas or TALEN modules are expressed in the plant cell only transiently. Theoretically, transient expression of the editing modules should limit unexpected effects compared to stable transformation. However, very few studies have measured the off-target and unpredicted effects of editing strategies on the plant genome, and none of them have compared these two major editing systems. We conducted, in Physcomitrium patens, a comprehensive genome-wide investigation of off-target mutations using either a CRISPR–Cas9 or a TALEN strategy. We observed a similar number of differences for the two editing strategies compared to control non-transfected plants, with an average of 8.25 SNVs and 19.5 InDels for the CRISPR-edited plants, and an average of 17.5 SNVs and 32 InDels for the TALEN-edited plants. Interestingly, a comparable number of SNVs and InDels could be detected in the PEG-treated control plants. This shows that except for the on-target modifications, the gene editing tools used in this study did not show a significant off-target activity nor unpredicted effects on the genome, and did not lead to transgene integration. The PEG treatment, a well-established biotechnological method, in itself, was the main source of mutations found in the edited plants.

As an ever-increasing population and the threats of climate change loom, feeding the world remains a major challenge. This collection showcases advances in plant genome editing research, recently published in Scientific Reports, touching on applications of CRISPR-based editing systems and crop breeding.

Depuis la décision de la Cour de justice de l'Union européenne (CJUE) du 25 juillet 2018, les organismes issus des nouvelles techniques de mutagénèse comme CRISPR doivent être considérés comme des OGM (acronyme de Organisme Génétiquement Modifié) et soumis à la même règlementation. Mais, ce que les juges peuvent interdire aux laboratoires, ils ne peuvent pas l'imposer à la nature. Or, les plantes s'échangent tous les jours des gènes entre elles ou avec des bactéries. L'une d'elles, Agrobacterium, est particulièrement active dans ce domaine.